(a) Field of the Invention
The present invention relates to an apparatus and method for compensating for a residual frequency offset after an initial synchronization process of frequency synchronization that plays an important role in a mobile communication system.
(b) Description of the Related Art
In general, data recovery is impossible to realize with a frequency offset in a SC-FDE (Single Carrier-Frequency Domain Equalizer) system as in all communication systems, so frequency synchronization is a significant factor in system performance.
Accordingly, a carrier-frequency offset leads to a deterioration of the system performance in the SC-FDE system.
In the conventional SC-FDE system, a known symbol (e.g., pilot) or data in the time domain are generally used for compensation of the frequency offset, as in a general single carrier system.
Even after estimation and compensation of the initial frequency offset, the system performance may deteriorate due to the residual frequency offset.
It is therefore required to track the residual frequency offset and compensate for the tracked residual frequency offset after estimation and compensation of the initial frequency offset so as to minimize the performance deterioration.